It's just Attack On Titan but they cut out the boring parts and put the action parts.
if you haven't watched Attack On Titan TV show and you won't waste you time on it i guess this is for you. but it's cuts the importent parts like character development and more ill say you should watch the orignal TV show and that's it. there is no more details we haven't got it's just the normal story but it's a lot more short.
it's not worth watching. if you want to watch the series agian watch this agian cuz you well get the best part of the sereis (the action parts)read more